drivers/iommu/amd_iommu_v2.c

   1 /*
   2  * Copyright (C) 2010-2012 Advanced Micro Devices, Inc.
   3  * Author: Joerg Roedel <jroedel@suse.de>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 as published
   7  * by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  17  */
  18
  19 #include <linux/mmu_notifier.h>
  20 #include <linux/amd-iommu.h>
  21 #include <linux/mm_types.h>
  22 #include <linux/profile.h>
  23 #include <linux/module.h>
  24 #include <linux/sched.h>
  25 #include <linux/sched/mm.h>
  26 #include <linux/iommu.h>
  27 #include <linux/wait.h>
  28 #include <linux/pci.h>
  29 #include <linux/gfp.h>
  30
  31 #include "amd_iommu_types.h"
  32 #include "amd_iommu_proto.h"
  33
  34 MODULE_LICENSE("GPL v2");
  35 MODULE_AUTHOR("Joerg Roedel <jroedel@suse.de>");
  36
  37 #define MAX_DEVICES             0x10000
  38 #define PRI_QUEUE_SIZE          512
  39
  40 struct pri_queue {
  41         atomic_t inflight;
  42         bool finish;
  43         int status;
  44 };
  45
  46 struct pasid_state {
  47         struct list_head list;                  /* For global state-list */
  48         atomic_t count;                         /* Reference count */
  49         unsigned mmu_notifier_count;            /* Counting nested mmu_notifier
  50                                                    calls */
  51         struct mm_struct *mm;                   /* mm_struct for the faults */
  52         struct mmu_notifier mn;                 /* mmu_notifier handle */
  53         struct pri_queue pri[PRI_QUEUE_SIZE];   /* PRI tag states */
  54         struct device_state *device_state;      /* Link to our device_state */
  55         int pasid;                              /* PASID index */
  56         bool invalid;                           /* Used during setup and
  57                                                    teardown of the pasid */
  58         spinlock_t lock;                        /* Protect pri_queues and
  59                                                    mmu_notifer_count */
  60         wait_queue_head_t wq;                   /* To wait for count == 0 */
  61 };
  62
  63 struct device_state {
  64         struct list_head list;
  65         u16 devid;
  66         atomic_t count;
  67         struct pci_dev *pdev;
  68         struct pasid_state **states;
  69         struct iommu_domain *domain;
  70         int pasid_levels;
  71         int max_pasids;
  72         amd_iommu_invalid_ppr_cb inv_ppr_cb;
  73         amd_iommu_invalidate_ctx inv_ctx_cb;
  74         spinlock_t lock;
  75         wait_queue_head_t wq;
  76 };
  77
  78 struct fault {
  79         struct work_struct work;
  80         struct device_state *dev_state;
  81         struct pasid_state *state;
  82         struct mm_struct *mm;
  83         u64 address;
  84         u16 devid;
  85         u16 pasid;
  86         u16 tag;
  87         u16 finish;
  88         u16 flags;
  89 };
  90
  91 static LIST_HEAD(state_list);
  92 static spinlock_t state_lock;
  93
  94 static struct workqueue_struct *iommu_wq;
  95
  96 static void free_pasid_states(struct device_state *dev_state);
  97
  98 static u16 device_id(struct pci_dev *pdev)
  99 {
 100         u16 devid;
 101
 102         devid = pdev->bus->number;
 103         devid = (devid << 8) | pdev->devfn;
 104
 105         return devid;
 106 }
 107
 108 static struct device_state *__get_device_state(u16 devid)
 109 {
 110         struct device_state *dev_state;
 111
 112         list_for_each_entry(dev_state, &state_list, list) {
 113                 if (dev_state->devid == devid)
 114                         return dev_state;
 115         }
 116
 117         return NULL;
 118 }
 119
 120 static struct device_state *get_device_state(u16 devid)
 121 {
 122         struct device_state *dev_state;
 123         unsigned long flags;
 124
 125         spin_lock_irqsave(&state_lock, flags);
 126         dev_state = __get_device_state(devid);
 127         if (dev_state != NULL)
 128                 atomic_inc(&dev_state->count);
 129         spin_unlock_irqrestore(&state_lock, flags);
 130
 131         return dev_state;
 132 }
 133
 134 static void free_device_state(struct device_state *dev_state)
 135 {
 136         struct iommu_group *group;
 137
 138         /*
 139          * First detach device from domain - No more PRI requests will arrive
 140          * from that device after it is unbound from the IOMMUv2 domain.
 141          */
 142         group = iommu_group_get(&dev_state->pdev->dev);
 143         if (WARN_ON(!group))
 144                 return;
 145
 146         iommu_detach_group(dev_state->domain, group);
 147
 148         iommu_group_put(group);
 149
 150         /* Everything is down now, free the IOMMUv2 domain */
 151         iommu_domain_free(dev_state->domain);
 152
 153         /* Finally get rid of the device-state */
 154         kfree(dev_state);
 155 }
 156
 157 static void put_device_state(struct device_state *dev_state)
 158 {
 159         if (atomic_dec_and_test(&dev_state->count))
 160                 wake_up(&dev_state->wq);
 161 }
 162
 163 /* Must be called under dev_state->lock */
 164 static struct pasid_state **__get_pasid_state_ptr(struct device_state *dev_state,
 165                                                   int pasid, bool alloc)
 166 {
 167         struct pasid_state **root, **ptr;
 168         int level, index;
 169
 170         level = dev_state->pasid_levels;
 171         root  = dev_state->states;
 172
 173         while (true) {
 174
 175                 index = (pasid >> (9 * level)) & 0x1ff;
 176                 ptr   = &root[index];
 177
 178                 if (level == 0)
 179                         break;
 180
 181                 if (*ptr == NULL) {
 182                         if (!alloc)
 183                                 return NULL;
 184
 185                         *ptr = (void *)get_zeroed_page(GFP_ATOMIC);
 186                         if (*ptr == NULL)
 187                                 return NULL;
 188                 }
 189
 190                 root   = (struct pasid_state **)*ptr;
 191                 level -= 1;
 192         }
 193
 194         return ptr;
 195 }
 196
 197 static int set_pasid_state(struct device_state *dev_state,
 198                            struct pasid_state *pasid_state,
 199                            int pasid)
 200 {
 201         struct pasid_state **ptr;
 202         unsigned long flags;
 203         int ret;
 204
 205         spin_lock_irqsave(&dev_state->lock, flags);
 206         ptr = __get_pasid_state_ptr(dev_state, pasid, true);
 207
 208         ret = -ENOMEM;
 209         if (ptr == NULL)
 210                 goto out_unlock;
 211
 212         ret = -ENOMEM;
 213         if (*ptr != NULL)
 214                 goto out_unlock;
 215
 216         *ptr = pasid_state;
 217
 218         ret = 0;
 219
 220 out_unlock:
 221         spin_unlock_irqrestore(&dev_state->lock, flags);
 222
 223         return ret;
 224 }
 225
 226 static void clear_pasid_state(struct device_state *dev_state, int pasid)
 227 {
 228         struct pasid_state **ptr;
 229         unsigned long flags;
 230
 231         spin_lock_irqsave(&dev_state->lock, flags);
 232         ptr = __get_pasid_state_ptr(dev_state, pasid, true);
 233
 234         if (ptr == NULL)
 235                 goto out_unlock;
 236
 237         *ptr = NULL;
 238
 239 out_unlock:
 240         spin_unlock_irqrestore(&dev_state->lock, flags);
 241 }
 242
 243 static struct pasid_state *get_pasid_state(struct device_state *dev_state,
 244                                            int pasid)
 245 {
 246         struct pasid_state **ptr, *ret = NULL;
 247         unsigned long flags;
 248
 249         spin_lock_irqsave(&dev_state->lock, flags);
 250         ptr = __get_pasid_state_ptr(dev_state, pasid, false);
 251
 252         if (ptr == NULL)
 253                 goto out_unlock;
 254
 255         ret = *ptr;
 256         if (ret)
 257                 atomic_inc(&ret->count);
 258
 259 out_unlock:
 260         spin_unlock_irqrestore(&dev_state->lock, flags);
 261
 262         return ret;
 263 }
 264
 265 static void free_pasid_state(struct pasid_state *pasid_state)
 266 {
 267         kfree(pasid_state);
 268 }
 269
 270 static void put_pasid_state(struct pasid_state *pasid_state)
 271 {
 272         if (atomic_dec_and_test(&pasid_state->count))
 273                 wake_up(&pasid_state->wq);
 274 }
 275
 276 static void put_pasid_state_wait(struct pasid_state *pasid_state)
 277 {
 278         atomic_dec(&pasid_state->count);
 279         wait_event(pasid_state->wq, !atomic_read(&pasid_state->count));
 280         free_pasid_state(pasid_state);
 281 }
 282
 283 static void unbind_pasid(struct pasid_state *pasid_state)
 284 {
 285         struct iommu_domain *domain;
 286
 287         domain = pasid_state->device_state->domain;
 288
 289         /*
 290          * Mark pasid_state as invalid, no more faults will we added to the
 291          * work queue after this is visible everywhere.
 292          */
 293         pasid_state->invalid = true;
 294
 295         /* Make sure this is visible */
 296         smp_wmb();
 297
 298         /* After this the device/pasid can't access the mm anymore */
 299         amd_iommu_domain_clear_gcr3(domain, pasid_state->pasid);
 300
 301         /* Make sure no more pending faults are in the queue */
 302         flush_workqueue(iommu_wq);
 303 }
 304
 305 static void free_pasid_states_level1(struct pasid_state **tbl)
 306 {
 307         int i;
 308
 309         for (i = 0; i < 512; ++i) {
 310                 if (tbl[i] == NULL)
 311                         continue;
 312
 313                 free_page((unsigned long)tbl[i]);
 314         }
 315 }
 316
 317 static void free_pasid_states_level2(struct pasid_state **tbl)
 318 {
 319         struct pasid_state **ptr;
 320         int i;
 321
 322         for (i = 0; i < 512; ++i) {
 323                 if (tbl[i] == NULL)
 324                         continue;
 325
 326                 ptr = (struct pasid_state **)tbl[i];
 327                 free_pasid_states_level1(ptr);
 328         }
 329 }
 330
 331 static void free_pasid_states(struct device_state *dev_state)
 332 {
 333         struct pasid_state *pasid_state;
 334         int i;
 335
 336         for (i = 0; i < dev_state->max_pasids; ++i) {
 337                 pasid_state = get_pasid_state(dev_state, i);
 338                 if (pasid_state == NULL)
 339                         continue;
 340
 341                 put_pasid_state(pasid_state);
 342
 343                 /*
 344                  * This will call the mn_release function and
 345                  * unbind the PASID
 346                  */
 347                 mmu_notifier_unregister(&pasid_state->mn, pasid_state->mm);
 348
 349                 put_pasid_state_wait(pasid_state); /* Reference taken in
 350                                                       amd_iommu_bind_pasid */
 351
 352                 /* Drop reference taken in amd_iommu_bind_pasid */
 353                 put_device_state(dev_state);
 354         }
 355
 356         if (dev_state->pasid_levels == 2)
 357                 free_pasid_states_level2(dev_state->states);
 358         else if (dev_state->pasid_levels == 1)
 359                 free_pasid_states_level1(dev_state->states);
 360         else
 361                 BUG_ON(dev_state->pasid_levels != 0);
 362
 363         free_page((unsigned long)dev_state->states);
 364 }
 365
 366 static struct pasid_state *mn_to_state(struct mmu_notifier *mn)
 367 {
 368         return container_of(mn, struct pasid_state, mn);
 369 }
 370
 371 static void __mn_flush_page(struct mmu_notifier *mn,
 372                             unsigned long address)
 373 {
 374         struct pasid_state *pasid_state;
 375         struct device_state *dev_state;
 376
 377         pasid_state = mn_to_state(mn);
 378         dev_state   = pasid_state->device_state;
 379
 380         amd_iommu_flush_page(dev_state->domain, pasid_state->pasid, address);
 381 }
 382
 383 static int mn_clear_flush_young(struct mmu_notifier *mn,
 384                                 struct mm_struct *mm,
 385                                 unsigned long start,
 386                                 unsigned long end)
 387 {
 388         for (; start < end; start += PAGE_SIZE)
 389                 __mn_flush_page(mn, start);
 390
 391         return 0;
 392 }
 393
 394 static void mn_invalidate_range(struct mmu_notifier *mn,
 395                                 struct mm_struct *mm,
 396                                 unsigned long start, unsigned long end)
 397 {
 398         struct pasid_state *pasid_state;
 399         struct device_state *dev_state;
 400
 401         pasid_state = mn_to_state(mn);
 402         dev_state   = pasid_state->device_state;
 403
 404         if ((start ^ (end - 1)) < PAGE_SIZE)
 405                 amd_iommu_flush_page(dev_state->domain, pasid_state->pasid,
 406                                      start);
 407         else
 408                 amd_iommu_flush_tlb(dev_state->domain, pasid_state->pasid);
 409 }
 410
 411 static void mn_release(struct mmu_notifier *mn, struct mm_struct *mm)
 412 {
 413         struct pasid_state *pasid_state;
 414         struct device_state *dev_state;
 415         bool run_inv_ctx_cb;
 416
 417         might_sleep();
 418
 419         pasid_state    = mn_to_state(mn);
 420         dev_state      = pasid_state->device_state;
 421         run_inv_ctx_cb = !pasid_state->invalid;
 422
 423         if (run_inv_ctx_cb && dev_state->inv_ctx_cb)
 424                 dev_state->inv_ctx_cb(dev_state->pdev, pasid_state->pasid);
 425
 426         unbind_pasid(pasid_state);
 427 }
 428
 429 static const struct mmu_notifier_ops iommu_mn = {
 430         .release                = mn_release,
 431         .clear_flush_young      = mn_clear_flush_young,
 432         .invalidate_range       = mn_invalidate_range,
 433 };
 434
 435 static void set_pri_tag_status(struct pasid_state *pasid_state,
 436                                u16 tag, int status)
 437 {
 438         unsigned long flags;
 439
 440         spin_lock_irqsave(&pasid_state->lock, flags);
 441         pasid_state->pri[tag].status = status;
 442         spin_unlock_irqrestore(&pasid_state->lock, flags);
 443 }
 444
 445 static void finish_pri_tag(struct device_state *dev_state,
 446                            struct pasid_state *pasid_state,
 447                            u16 tag)
 448 {
 449         unsigned long flags;
 450
 451         spin_lock_irqsave(&pasid_state->lock, flags);
 452         if (atomic_dec_and_test(&pasid_state->pri[tag].inflight) &&
 453             pasid_state->pri[tag].finish) {
 454                 amd_iommu_complete_ppr(dev_state->pdev, pasid_state->pasid,
 455                                        pasid_state->pri[tag].status, tag);
 456                 pasid_state->pri[tag].finish = false;
 457                 pasid_state->pri[tag].status = PPR_SUCCESS;
 458         }
 459         spin_unlock_irqrestore(&pasid_state->lock, flags);
 460 }
 461
 462 static void handle_fault_error(struct fault *fault)
 463 {
 464         int status;
 465
 466         if (!fault->dev_state->inv_ppr_cb) {
 467                 set_pri_tag_status(fault->state, fault->tag, PPR_INVALID);
 468                 return;
 469         }
 470
 471         status = fault->dev_state->inv_ppr_cb(fault->dev_state->pdev,
 472                                               fault->pasid,
 473                                               fault->address,
 474                                               fault->flags);
 475         switch (status) {
 476         case AMD_IOMMU_INV_PRI_RSP_SUCCESS:
 477                 set_pri_tag_status(fault->state, fault->tag, PPR_SUCCESS);
 478                 break;
 479         case AMD_IOMMU_INV_PRI_RSP_INVALID:
 480                 set_pri_tag_status(fault->state, fault->tag, PPR_INVALID);
 481                 break;
 482         case AMD_IOMMU_INV_PRI_RSP_FAIL:
 483                 set_pri_tag_status(fault->state, fault->tag, PPR_FAILURE);
 484                 break;
 485         default:
 486                 BUG();
 487         }
 488 }
 489
 490 static bool access_error(struct vm_area_struct *vma, struct fault *fault)
 491 {
 492         unsigned long requested = 0;
 493
 494         if (fault->flags & PPR_FAULT_EXEC)
 495                 requested |= VM_EXEC;
 496
 497         if (fault->flags & PPR_FAULT_READ)
 498                 requested |= VM_READ;
 499
 500         if (fault->flags & PPR_FAULT_WRITE)
 501                 requested |= VM_WRITE;
 502
 503         return (requested & ~vma->vm_flags) != 0;
 504 }
 505
 506 static void do_fault(struct work_struct *work)
 507 {
 508         struct fault *fault = container_of(work, struct fault, work);
 509         struct vm_area_struct *vma;
 510         vm_fault_t ret = VM_FAULT_ERROR;
 511         unsigned int flags = 0;
 512         struct mm_struct *mm;
 513         u64 address;
 514
 515         mm = fault->state->mm;
 516         address = fault->address;
 517
 518         if (fault->flags & PPR_FAULT_USER)
 519                 flags |= FAULT_FLAG_USER;
 520         if (fault->flags & PPR_FAULT_WRITE)
 521                 flags |= FAULT_FLAG_WRITE;
 522         flags |= FAULT_FLAG_REMOTE;
 523
 524         down_read(&mm->mmap_sem);
 525         vma = find_extend_vma(mm, address);
 526         if (!vma || address < vma->vm_start)
 527                 /* failed to get a vma in the right range */
 528                 goto out;
 529
 530         /* Check if we have the right permissions on the vma */
 531         if (access_error(vma, fault))
 532                 goto out;
 533
 534         ret = handle_mm_fault(vma, address, flags);
 535 out:
 536         up_read(&mm->mmap_sem);
 537
 538         if (ret & VM_FAULT_ERROR)
 539                 /* failed to service fault */
 540                 handle_fault_error(fault);
 541
 542         finish_pri_tag(fault->dev_state, fault->state, fault->tag);
 543
 544         put_pasid_state(fault->state);
 545
 546         kfree(fault);
 547 }
 548
 549 static int ppr_notifier(struct notifier_block *nb, unsigned long e, void *data)
 550 {
 551         struct amd_iommu_fault *iommu_fault;
 552         struct pasid_state *pasid_state;
 553         struct device_state *dev_state;
 554         unsigned long flags;
 555         struct fault *fault;
 556         bool finish;
 557         u16 tag, devid;
 558         int ret;
 559         struct iommu_dev_data *dev_data;
 560         struct pci_dev *pdev = NULL;
 561
 562         iommu_fault = data;
 563         tag         = iommu_fault->tag & 0x1ff;
 564         finish      = (iommu_fault->tag >> 9) & 1;
 565
 566         devid = iommu_fault->device_id;
 567         pdev = pci_get_domain_bus_and_slot(0, PCI_BUS_NUM(devid),
 568                                            devid & 0xff);
 569         if (!pdev)
 570                 return -ENODEV;
 571         dev_data = get_dev_data(&pdev->dev);
 572
 573         /* In kdump kernel pci dev is not initialized yet -> send INVALID */
 574         ret = NOTIFY_DONE;
 575         if (translation_pre_enabled(amd_iommu_rlookup_table[devid])
 576                 && dev_data->defer_attach) {
 577                 amd_iommu_complete_ppr(pdev, iommu_fault->pasid,
 578                                        PPR_INVALID, tag);
 579                 goto out;
 580         }
 581
 582         dev_state = get_device_state(iommu_fault->device_id);
 583         if (dev_state == NULL)
 584                 goto out;
 585
 586         pasid_state = get_pasid_state(dev_state, iommu_fault->pasid);
 587         if (pasid_state == NULL || pasid_state->invalid) {
 588                 /* We know the device but not the PASID -> send INVALID */
 589                 amd_iommu_complete_ppr(dev_state->pdev, iommu_fault->pasid,
 590                                        PPR_INVALID, tag);
 591                 goto out_drop_state;
 592         }
 593
 594         spin_lock_irqsave(&pasid_state->lock, flags);
 595         atomic_inc(&pasid_state->pri[tag].inflight);
 596         if (finish)
 597                 pasid_state->pri[tag].finish = true;
 598         spin_unlock_irqrestore(&pasid_state->lock, flags);
 599
 600         fault = kzalloc(sizeof(*fault), GFP_ATOMIC);
 601         if (fault == NULL) {
 602                 /* We are OOM - send success and let the device re-fault */
 603                 finish_pri_tag(dev_state, pasid_state, tag);
 604                 goto out_drop_state;
 605         }
 606
 607         fault->dev_state = dev_state;
 608         fault->address   = iommu_fault->address;
 609         fault->state     = pasid_state;
 610         fault->tag       = tag;
 611         fault->finish    = finish;
 612         fault->pasid     = iommu_fault->pasid;
 613         fault->flags     = iommu_fault->flags;
 614         INIT_WORK(&fault->work, do_fault);
 615
 616         queue_work(iommu_wq, &fault->work);
 617
 618         ret = NOTIFY_OK;
 619
 620 out_drop_state:
 621
 622         if (ret != NOTIFY_OK && pasid_state)
 623                 put_pasid_state(pasid_state);
 624
 625         put_device_state(dev_state);
 626
 627 out:
 628         return ret;
 629 }
 630
 631 static struct notifier_block ppr_nb = {
 632         .notifier_call = ppr_notifier,
 633 };
 634
 635 int amd_iommu_bind_pasid(struct pci_dev *pdev, int pasid,
 636                          struct task_struct *task)
 637 {
 638         struct pasid_state *pasid_state;
 639         struct device_state *dev_state;
 640         struct mm_struct *mm;
 641         u16 devid;
 642         int ret;
 643
 644         might_sleep();
 645
 646         if (!amd_iommu_v2_supported())
 647                 return -ENODEV;
 648
 649         devid     = device_id(pdev);
 650         dev_state = get_device_state(devid);
 651
 652         if (dev_state == NULL)
 653                 return -EINVAL;
 654
 655         ret = -EINVAL;
 656         if (pasid < 0 || pasid >= dev_state->max_pasids)
 657                 goto out;
 658
 659         ret = -ENOMEM;
 660         pasid_state = kzalloc(sizeof(*pasid_state), GFP_KERNEL);
 661         if (pasid_state == NULL)
 662                 goto out;
 663
 664
 665         atomic_set(&pasid_state->count, 1);
 666         init_waitqueue_head(&pasid_state->wq);
 667         spin_lock_init(&pasid_state->lock);
 668
 669         mm                        = get_task_mm(task);
 670         pasid_state->mm           = mm;
 671         pasid_state->device_state = dev_state;
 672         pasid_state->pasid        = pasid;
 673         pasid_state->invalid      = true; /* Mark as valid only if we are
 674                                              done with setting up the pasid */
 675         pasid_state->mn.ops       = &iommu_mn;
 676
 677         if (pasid_state->mm == NULL)
 678                 goto out_free;
 679
 680         mmu_notifier_register(&pasid_state->mn, mm);
 681
 682         ret = set_pasid_state(dev_state, pasid_state, pasid);
 683         if (ret)
 684                 goto out_unregister;
 685
 686         ret = amd_iommu_domain_set_gcr3(dev_state->domain, pasid,
 687                                         __pa(pasid_state->mm->pgd));
 688         if (ret)
 689                 goto out_clear_state;
 690
 691         /* Now we are ready to handle faults */
 692         pasid_state->invalid = false;
 693
 694         /*
 695          * Drop the reference to the mm_struct here. We rely on the
 696          * mmu_notifier release call-back to inform us when the mm
 697          * is going away.
 698          */
 699         mmput(mm);
 700
 701         return 0;
 702
 703 out_clear_state:
 704         clear_pasid_state(dev_state, pasid);
 705
 706 out_unregister:
 707         mmu_notifier_unregister(&pasid_state->mn, mm);
 708         mmput(mm);
 709
 710 out_free:
 711         free_pasid_state(pasid_state);
 712
 713 out:
 714         put_device_state(dev_state);
 715
 716         return ret;
 717 }
 718 EXPORT_SYMBOL(amd_iommu_bind_pasid);
 719
 720 void amd_iommu_unbind_pasid(struct pci_dev *pdev, int pasid)
 721 {
 722         struct pasid_state *pasid_state;
 723         struct device_state *dev_state;
 724         u16 devid;
 725
 726         might_sleep();
 727
 728         if (!amd_iommu_v2_supported())
 729                 return;
 730
 731         devid = device_id(pdev);
 732         dev_state = get_device_state(devid);
 733         if (dev_state == NULL)
 734                 return;
 735
 736         if (pasid < 0 || pasid >= dev_state->max_pasids)
 737                 goto out;
 738
 739         pasid_state = get_pasid_state(dev_state, pasid);
 740         if (pasid_state == NULL)
 741                 goto out;
 742         /*
 743          * Drop reference taken here. We are safe because we still hold
 744          * the reference taken in the amd_iommu_bind_pasid function.
 745          */
 746         put_pasid_state(pasid_state);
 747
 748         /* Clear the pasid state so that the pasid can be re-used */
 749         clear_pasid_state(dev_state, pasid_state->pasid);
 750
 751         /*
 752          * Call mmu_notifier_unregister to drop our reference
 753          * to pasid_state->mm
 754          */
 755         mmu_notifier_unregister(&pasid_state->mn, pasid_state->mm);
 756
 757         put_pasid_state_wait(pasid_state); /* Reference taken in
 758                                               amd_iommu_bind_pasid */
 759 out:
 760         /* Drop reference taken in this function */
 761         put_device_state(dev_state);
 762
 763         /* Drop reference taken in amd_iommu_bind_pasid */
 764         put_device_state(dev_state);
 765 }
 766 EXPORT_SYMBOL(amd_iommu_unbind_pasid);
 767
 768 int amd_iommu_init_device(struct pci_dev *pdev, int pasids)
 769 {
 770         struct device_state *dev_state;
 771         struct iommu_group *group;
 772         unsigned long flags;
 773         int ret, tmp;
 774         u16 devid;
 775
 776         might_sleep();
 777
 778         if (!amd_iommu_v2_supported())
 779                 return -ENODEV;
 780
 781         if (pasids <= 0 || pasids > (PASID_MASK + 1))
 782                 return -EINVAL;
 783
 784         devid = device_id(pdev);
 785
 786         dev_state = kzalloc(sizeof(*dev_state), GFP_KERNEL);
 787         if (dev_state == NULL)
 788                 return -ENOMEM;
 789
 790         spin_lock_init(&dev_state->lock);
 791         init_waitqueue_head(&dev_state->wq);
 792         dev_state->pdev  = pdev;
 793         dev_state->devid = devid;
 794
 795         tmp = pasids;
 796         for (dev_state->pasid_levels = 0; (tmp - 1) & ~0x1ff; tmp >>= 9)
 797                 dev_state->pasid_levels += 1;
 798
 799         atomic_set(&dev_state->count, 1);
 800         dev_state->max_pasids = pasids;
 801
 802         ret = -ENOMEM;
 803         dev_state->states = (void *)get_zeroed_page(GFP_KERNEL);
 804         if (dev_state->states == NULL)
 805                 goto out_free_dev_state;
 806
 807         dev_state->domain = iommu_domain_alloc(&pci_bus_type);
 808         if (dev_state->domain == NULL)
 809                 goto out_free_states;
 810
 811         amd_iommu_domain_direct_map(dev_state->domain);
 812
 813         ret = amd_iommu_domain_enable_v2(dev_state->domain, pasids);
 814         if (ret)
 815                 goto out_free_domain;
 816
 817         group = iommu_group_get(&pdev->dev);
 818         if (!group) {
 819                 ret = -EINVAL;
 820                 goto out_free_domain;
 821         }
 822
 823         ret = iommu_attach_group(dev_state->domain, group);
 824         if (ret != 0)
 825                 goto out_drop_group;
 826
 827         iommu_group_put(group);
 828
 829         spin_lock_irqsave(&state_lock, flags);
 830
 831         if (__get_device_state(devid) != NULL) {
 832                 spin_unlock_irqrestore(&state_lock, flags);
 833                 ret = -EBUSY;
 834                 goto out_free_domain;
 835         }
 836
 837         list_add_tail(&dev_state->list, &state_list);
 838
 839         spin_unlock_irqrestore(&state_lock, flags);
 840
 841         return 0;
 842
 843 out_drop_group:
 844         iommu_group_put(group);
 845
 846 out_free_domain:
 847         iommu_domain_free(dev_state->domain);
 848
 849 out_free_states:
 850         free_page((unsigned long)dev_state->states);
 851
 852 out_free_dev_state:
 853         kfree(dev_state);
 854
 855         return ret;
 856 }
 857 EXPORT_SYMBOL(amd_iommu_init_device);
 858
 859 void amd_iommu_free_device(struct pci_dev *pdev)
 860 {
 861         struct device_state *dev_state;
 862         unsigned long flags;
 863         u16 devid;
 864
 865         if (!amd_iommu_v2_supported())
 866                 return;
 867
 868         devid = device_id(pdev);
 869
 870         spin_lock_irqsave(&state_lock, flags);
 871
 872         dev_state = __get_device_state(devid);
 873         if (dev_state == NULL) {
 874                 spin_unlock_irqrestore(&state_lock, flags);
 875                 return;
 876         }
 877
 878         list_del(&dev_state->list);
 879
 880         spin_unlock_irqrestore(&state_lock, flags);
 881
 882         /* Get rid of any remaining pasid states */
 883         free_pasid_states(dev_state);
 884
 885         put_device_state(dev_state);
 886         /*
 887          * Wait until the last reference is dropped before freeing
 888          * the device state.
 889          */
 890         wait_event(dev_state->wq, !atomic_read(&dev_state->count));
 891         free_device_state(dev_state);
 892 }
 893 EXPORT_SYMBOL(amd_iommu_free_device);
 894
 895 int amd_iommu_set_invalid_ppr_cb(struct pci_dev *pdev,
 896                                  amd_iommu_invalid_ppr_cb cb)
 897 {
 898         struct device_state *dev_state;
 899         unsigned long flags;
 900         u16 devid;
 901         int ret;
 902
 903         if (!amd_iommu_v2_supported())
 904                 return -ENODEV;
 905
 906         devid = device_id(pdev);
 907
 908         spin_lock_irqsave(&state_lock, flags);
 909
 910         ret = -EINVAL;
 911         dev_state = __get_device_state(devid);
 912         if (dev_state == NULL)
 913                 goto out_unlock;
 914
 915         dev_state->inv_ppr_cb = cb;
 916
 917         ret = 0;
 918
 919 out_unlock:
 920         spin_unlock_irqrestore(&state_lock, flags);
 921
 922         return ret;
 923 }
 924 EXPORT_SYMBOL(amd_iommu_set_invalid_ppr_cb);
 925
 926 int amd_iommu_set_invalidate_ctx_cb(struct pci_dev *pdev,
 927                                     amd_iommu_invalidate_ctx cb)
 928 {
 929         struct device_state *dev_state;
 930         unsigned long flags;
 931         u16 devid;
 932         int ret;
 933
 934         if (!amd_iommu_v2_supported())
 935                 return -ENODEV;
 936
 937         devid = device_id(pdev);
 938
 939         spin_lock_irqsave(&state_lock, flags);
 940
 941         ret = -EINVAL;
 942         dev_state = __get_device_state(devid);
 943         if (dev_state == NULL)
 944                 goto out_unlock;
 945
 946         dev_state->inv_ctx_cb = cb;
 947
 948         ret = 0;
 949
 950 out_unlock:
 951         spin_unlock_irqrestore(&state_lock, flags);
 952
 953         return ret;
 954 }
 955 EXPORT_SYMBOL(amd_iommu_set_invalidate_ctx_cb);
 956
 957 static int __init amd_iommu_v2_init(void)
 958 {
 959         int ret;
 960
 961         pr_info("AMD IOMMUv2 driver by Joerg Roedel <jroedel@suse.de>\n");
 962
 963         if (!amd_iommu_v2_supported()) {
 964                 pr_info("AMD IOMMUv2 functionality not available on this system\n");
 965                 /*
 966                  * Load anyway to provide the symbols to other modules
 967                  * which may use AMD IOMMUv2 optionally.
 968                  */
 969                 return 0;
 970         }
 971
 972         spin_lock_init(&state_lock);
 973
 974         ret = -ENOMEM;
 975         iommu_wq = alloc_workqueue("amd_iommu_v2", WQ_MEM_RECLAIM, 0);
 976         if (iommu_wq == NULL)
 977                 goto out;
 978
 979         amd_iommu_register_ppr_notifier(&ppr_nb);
 980
 981         return 0;
 982
 983 out:
 984         return ret;
 985 }
 986
 987 static void __exit amd_iommu_v2_exit(void)
 988 {
 989         struct device_state *dev_state;
 990         int i;
 991
 992         if (!amd_iommu_v2_supported())
 993                 return;
 994
 995         amd_iommu_unregister_ppr_notifier(&ppr_nb);
 996
 997         flush_workqueue(iommu_wq);
 998
 999         /*
1000          * The loop below might call flush_workqueue(), so call
1001          * destroy_workqueue() after it
1002          */
1003         for (i = 0; i < MAX_DEVICES; ++i) {
1004                 dev_state = get_device_state(i);
1005
1006                 if (dev_state == NULL)
1007                         continue;
1008
1009                 WARN_ON_ONCE(1);
1010
1011                 put_device_state(dev_state);
1012                 amd_iommu_free_device(dev_state->pdev);
1013         }
1014
1015         destroy_workqueue(iommu_wq);
1016 }
1017
1018 module_init(amd_iommu_v2_init);
1019 module_exit(amd_iommu_v2_exit);